Specifying the read mode

Programming Interfaces

External Program Interfaces : Sockets : Read, writing, and managing sockets on clients and servers : Reading data on a socket : Specifying the read mode

You can specify mode using a compiler constant as shown in the following table.

Table 67. Socket reading modes
Compiler constant	Value	Description
READ-AVAILABLE	1	The READ( ) method blocks until at least one (1) byte is available on the socket and reads the number of bytes that are available up to a maximum of bytes-to-read bytes.
READ-EXACT-NUM	2	(Default) The READ( ) method blocks until bytes-to-read bytes are available to read from the socket.

Thus, you can have the READ( ) method block until exactly the specified number of bytes are read (the default), or until all available bytes are read up to a maximum number allowed.

The appropriate reading mode to use depends on your application requirements. Note, however, that if you specify READ-EXACT-NUM, the READ( ) method blocks until it reads the specified number of bytes (no matter how long it takes) or until the socket is disconnected (whatever happens first).